Sonographic imaging of the soft-tissue thickness of the edentulous maxilla.

For preimplantologic evaluation and diagnosis, there are various mechanical methods for measuring the thickness of the soft tissue and thus indirectly measuring the osseous bed of the implant. This study evaluated the use of real-time sonography for analyzing the soft-tissue thickness of the entire edentulous maxilla in an anatomic examination of human cadaver specimens. The data obtained were compared with findings from the usual needle measurement method. The ultrasound measurement method produced realistic data in all measurement points of all sectional planes selected.

[Reference values for the pulsatility index and the resistance index of blood flow curves of the umbilical artery and fetal aorta in the 3d trimester]. / Referenzwerte für den Pulsatilitätsindex und den Resistance-Index von Blutflusskurven der Arteria umbilicalis und der fetalen Aorta im dritten Trimenon.

In 209 pregnancies without complications we recorded blood velocity waveforms of the umbilical artery and the foetal aorta between 29 and 42 weeks of gestation by means of a Duplex-pulsed Doppler system (umbilical artery: n = 276; foetal aorta: n = 244). We calculated the pulsatility index (PI) and the resistance index (RI). Both indices were normally distributed. The regression lines and reference ranges for the 95% confidence intervals are shown. The PI as well as the RI of waveforms of the umbilical artery demonstrated a significant fall with increasing gestation. The PI of the foetal aorta demonstrated a gentle, non-significant fall; RI showed no changes throughout the third trimester. Comparisons with the reference ranges published by other authors are discussed.

[Comparison of the clinical value of 2 frequently used indices of fetal blood flow analysis (pulsatility index PI and resistance index RI)]. / Vergleich der klinischen Wertigkeit zweier zur fetalen Blutflussanalyse häufig verwendeter Indices (Pulsatilitätsindex PI und Resistanceindex RI).

249 blood-flow measurements were carried out with pulsed Doppler-ultrasound in the umbilical arteries and the descending aorta of 188 fetuses. The PI and the RI of the recorded flowpatterns were calculated. In a retrospective study we then calculated the validity of the prediction of a pathological fetal outcome, i.e. a SGA-fetus and/or perinatal morbidity, for both indices. The sensitivity of the PI is 63%, the specificity was 98%, the sensitivity of the RI was 40%, and the specificity 98%. Therefore the sensitivity of the PI is significantly higher than that of the RI (p less than 0.05). In the second, prospective part of the study these results could be verified by means of an equivalent number of measurements to the first group (n = 249) with 178 fetuses. All the jeopardized fetuses with IUGR and perinatal morbidity (n = 13) were detected by an increased PI, but even in this group the sensitivity of the RI was only 54%. The possible reasons for these results are discussed, taking into account the different characteristics of the two indices and the influence of the heart rate on both of them.

Preventive action of phentolamine on adrenaline induced blood glucose elevation in humans.

A comparison of the action of adrenaline infusion and a combined adrenaline + alpha blocker (phentolamine, Regitine) infusion on blood glucose (BG), plasma immunoreactive insulin (IRI), BG/IRI ratio, C-peptide, and plasma cortisol levels was made in healthy young human subjects. The purpose of the experiment was to check, whether alpha block could abolish adrenaline-induced enhancement of blood glucose levels. The results show that during enhanced adrenaline levels, the use of regitine could indeed normalize blood glucose levels, not so much by increasing the IRI secretion, but by diminishing adrenaline-induced liver glycogenolysis via alpha receptors. This could be a model to prevent stress (adrenaline) induced metabolic deviations in diabetics, especially before and during predictable stress situations, e.g. examinations or surgery.

[Clinical value of fetal flow measurements with pulsed Doppler ultrasound]. / Die klinische Aussagekraft fetaler Flow-Messungen mittels gepulstem Doppler-Ultraschall.

326 fetal flow-measurements with Doppler ultrasound were carried out in the umbilical arteries and fetal aortas of 236 newborn babies. The pulsatility index and the resistance index were used for the flowprofile analysis. The dystrophy rate and the rate of serious perinatological problems of newborn babies with pathological flow (n = 26) are compared with those of newborn babies with a normal flow. It appears that in the group with pathological flowindices, the dystrophy rate is 7.8 times and the morbidity rate 17 times higher. Most important, however, was the fact that all endangered SGA fetuses were diagnosed with flowmeasurements while SGA fetuses with a normal flow had no perinatological problems at all. Enddiastolic flow reductions, based on an increased placental resistance, are provable relatively early, whereas a beginning centralization of the fetal circulation is only recognizable in a closer temporal connection with the fetal imperilment on account of pathological flowprofiles.

Long-term adrenergic beta-action decreases and alpha-action enhances corticosterone levels in rats.

A 20 h hyperadrenalinemia in rats was produced by subcutaneously implanted A-retard tablets with an output rate of 1.8 micrograms/min/250 g. This caused a moderate (6 h, 20 h) to expressed (12 h) rise in Corticosterone. Concomitant beta-blockade leads to equal (12 h, 20 h) or even more expressed (6 h) enhancement of plasma corticosterone, while A + alpha-blockade lowers those levels significantly against A or A + Prop treated animals. At 6 and 20 h they are even significantly lower than control values. We therefore conclude that enhanced alpha-adrenergic influence increases and beta-adrenergic influence decreases plasma Corticosterone levels in rats.

Decrease of rat-liver-T4-5'-deiodinase activity during chronical isoprenaline beta-action in vivo.

Pure adrenergic beta-action, brought about by long-term adrenaline + regitine application in rats, was able to increase liver T4-5'-deiodinase activity for 8 h (Nauman et al. 1984a). Long-term isoprenaline application without alpha-blocking yielded contrary results. One of the compensatory mechanism to be probably blamed could have been the very high endogenous adrenaline-levels (Porta et al. 1985). Simultaneous treatment with isoprenaline and alpha-methyltyrosinemethylester did not settle the problem since even then deiodinase activity was still drastically decreased. Two more components have been found which could very well be the reason for that "paradox beta-action" in vivo, namely very low glucose and insulin levels, both of which are known to influence deiodinase activity. In vivo--contrary to in vitro--it is seemingly not possible that catecholaminergic beta-action could increase the peripheral production of T3 unless general alpha-blocking took place.

Long-term application of some catecholamines elevates levels of other catecholamines in rats.

Male Sprague-Dawley rats were treated during 20 h with subcutaneously implanted tablets (controlled release systems) containing either adrenaline (A), noradrenaline (NA), isoprenaline (ISO) or just placebos. Levels of the exogenously administered catecholamines (CA) in plasma and liver homogenate were significantly higher than in controls throughout the test time. During NA application endogeneous A and dopamine (DA) plasma values rose considerably, while ISO application enhanced endogenous NA and A levels. Adrenaline application increased NA and DA plasma levels. Several possibilities for this phenomenon are discussed, and it is concluded that previous papers dealing with observations of long term action of CA's should be reevaluated unless the influence of the artificially given CA on the elevation of endogenous CA's has been already taken into consideration.

Peculiar long-term effects of catecholamines and their blockers in rats on insulin, glucose and pancreas.

To be able to study the long-term effects of moderately enhanced catecholamine levels in rats, we developed subcutaneously implantable retard systems, granting a linear output of various agents throughout the test time. Adrenaline application leads to hyperglycemia without elevation of serum immune-reactive-insulin (IRI) during 20 h of uninterrupted adrenaline (A) action. This we call an A-induced diabetes like reaction. It could be completely abolished by simultaneous application of low phentolamine (Regitin) doses. Simultaneous application of propranolol (P) gradually diminished blood glucose levels from about 200 mg/dl after 6 h to 120 mg/dl after 20 h. Since here insulin levels are uniformly low, decline of blood glucose could not be due to enhanced insulin-action. The moderate hyperglycemia after 6 h isoprenaline (ISO)-treatment alone goes with a hyperinsulinemia at the same time. Obviously this hyperinsulinemia cannot cope with the increased blood glucose probably due to enhanced liver-glycogenolysis by intact alpha-action. Later on insulin--despite of beta-action on pancreas--declines strictly proportional with diminishing blood-glucose-levels. A comparison between the action of catecholamines and their blockers showed that alpha-blockers tend to diminish blood glucose levels by two independent ways, namely by the inhibitory action on pancreas and the inhibitory action on liver glycogenolysis.